Skill New

Meta-skill that creates new skills consistently. Produces a SKILL.md that passes tools/lint-skills.py --strict on first save, with placeholders that force the author to fill in the load-bearing parts.

Overview

Hand-authored skills drift in shape. Some have argument hints, some do not. Some declare allowed tools, some do not. The 6-section template gets partially adopted. This skill removes the drift by scaffolding from a single source of truth and immediately validating the result.

When to Use

• User says "new skill X", "scaffold skill", "create a slash command for X"
• A new repeatable workflow has emerged that justifies a slash command
• A retrospective surfaced a pattern that should become a skill

Do NOT use when:

• The behavior belongs in a rule, hook, or agent instead (consider first)
• The workflow is too project-specific to live in the global config
• An existing skill already covers the use case (extend it)

Process

1. Resolve name. Accept a kebab-case identifier (e.g., interview-me). Reject names that already exist under skills/. Reject names that conflict with an existing slash command vocabulary.
2. Gather inputs. Ask one question at a time, using AskUserQuestion:
   • Invocation. Pick model-invocation only when the agent must reach the skill on its own.
     • Model-invoked, the default: the description is loaded into every session and carries the trigger phrases plus positive routing such as "for X, use /y".
     • User-invoked: add disable-model-invocation: true. The description is one human-facing sentence for the / menu, with no trigger list, and costs zero context. Claude cannot run it through the Skill tool, so no other skill or rule may hand off to it.
   • Description matching that invocation choice, quoted when it contains :
   • Argument hint (example invocations)
   • Tool scope: which tools the skill pre-approves (allowed-tools) or which to deny (disallowed-tools)
   • Sensitive flag (true for destructive or privileged skills)
   • Scripts: does any step run a deterministic operation the agent would otherwise regenerate on every run, such as parsing, validating, or formatting? Ship it as a script in the skill folder and call it, rather than describing it in prose.
3. Scaffold. Create skills/<name>/SKILL.md with the frontmatter block and the six required headings. Each section gets a placeholder paragraph that names what belongs there. Every Process step ends on a checkable completion criterion, per Completion Criteria in standards/agent-instruction-files.md.
4. Validate. Run python3 tools/lint-skills.py --strict skills/<name>/SKILL.md. Block return until the linter passes.
5. Prove it bites. For every linter, hook, or check the skill introduces, run it three times: on the clean tree it passes, with one planted violation it fails, and with the violation removed it passes again. Keep the output of all three runs as evidence.
6. Register. If a new on-demand rule trigger applies, add an entry to rules/index.yml. If the skill should appear in the README skill table, update it.

Common Rationalizations

• "I will copy from another skill instead": copying introduces drift. Scaffold from the template.
• "I will fill the sections in later": the linter blocks merging until the sections exist. Fill them now.
• "I will skip the linter, the file is fine": strict mode catches missing fields you forgot. Run it.
• "The description is good enough at 20 characters": short descriptions fail discovery. Aim for 50+.

Red Flags

• About to commit a skill where argument-hint is empty or absent
• About to commit a skill with neither allowed-tools nor disallowed-tools
• About to commit a skill missing one of the six required sections
• About to invoke this skill for editing an existing SKILL.md
• About to scaffold a skill whose name collides with an existing one

Verification

• python3 tools/lint-skills.py --strict skills/<name>/SKILL.md returns 0
• Every check the skill introduces passed clean, failed on a planted violation, and passed again once the violation was removed
• A user-invoked skill has disable-model-invocation: true and a one-sentence description; a model-invoked skill has trigger phrases and positive routing
• README skill table updated
• rules/index.yml updated if the skill is triggered on-demand by keywords
• Frontmatter name matches the directory name exactly
• All six required sections present with non-empty bodies